A Scottish holidaymaker has gone missing during a weekend break in Prague after witnesses reportedly saw him jump off a party boat.

Joop Sparkes, 29, travelled to the Czech Republic with friends on Friday and had been enjoying the capital city's bars and nightclubs. On Saturday night, the group departed on a party boat that sailed off from outside the President Hotel Prague.

During the early hours of Sunday morning, while his friends were at the bar, Mr Sparkes was witnessed jumping into the Vltava river "for a swim". Mr Sparkes, from Galashiels in the Scottish Borders, has since failed to appear or get in touch with his family and friends.

His sister, Jodie Wilson, told Sky News: "We're going through so many emotions. "One minute we're all breaking down and falling to bits, but then we realise that we've got to hold it together because we need to focus and put all our effort into finding him." Ms Wilson travelled to Prague on Monday.

She has been accompanied by Mr Sparkes' aunty, Gill Bunyan, as well as his girlfriend, Charley Maben, and her mum. Ms Wilson said there has been a police boat on the river and divers out searching for her brother.

However, she has not seen any other officer along the riverbank as the visiting group carry out their own searches from the sides. Sky News has contacted Police of the Czech Republic for comment.

Following the incident, Mr Sparkes' friends initially waited for him after their boat docked. The group, who had his phone and wallet, hoped he had made his way back to the hostel where they were staying, but he failed to appear.

Ms Wilson said a woman on the boat reportedly saw Mr Sparkes swimming towards the opposite side of the river to the President Hotel Prague. She said: "But when I asked if it looked like he was swimming okay or if he was maybe struggling, she couldn't say as it was quite dark." Ms Wilson said it was out of character for Mr Sparkes to be out of contact with his loved ones.

She said he returned to the hostel on the Friday evening on his own to charge his phone so he could let his partner know he was safe. Ms Wilson said: "Joop would never, ever leave Charley or his family wondering where he was, if he had any way of letting us know." Read more from Sky News:Schoolboy killed in sword attack named as family pays tribute to 'wonderful child'Ex-politician seen beating his wife to death in CCTV footage Ms Wilson said a number of calls have been made to local hospitals to see if Mr Sparkes had been admitted for treatment.

She said the group are "unsure what to do" next, amid a "language barrier problem.